Liquid limit of a soil indicates its
Liquid limit is the water content where the soil starts to behave as a liquid. Liquid limit is measured by placing a clay sample in a standard cup and making a separation (groove) using a spatula. The cup is dropped till the separation vanishes. The water content of the soil is obtained from this sample.
An undisturbed soil sample has a plastic limit of 25%, a natural moisture content of 40% and liquidity index of 50%, Its liquid limit in % will be
⇒ Ip = 30%
Also Ip = wl - wp
⇒ Wl = 30 + 25 = 55%
A well graded soil has a coefficient of curvature between
The ratio of the undisturbed shear strength to the remoulded shear strength in cohesive soil under undrained conditions is
at unaltered water condition i.e. at undrained condition. Remoulded shear strength is less than undisturbed shear strength.
Number of phases in soil mass is:
Soil has three phase representation as follows,
Which of the following is a measure of particle size range?
The uniformity of a soil is expressed qualitatively by a term known as uniformity coefficient, Cu, given by,
The larger the numerical value of Cu, the more is the range of particles.
The ratio for a soil mass is called:
The consistency index indicates the consistency (firmness) of a soil. It shows the nearness of the water content of the soil to its plastic limit. A soil with a consistency index of zero is at the liquid limit. It is extremely soft and has negligible shear strength. On the other hand, a soil at a water content equal to the plastic limit has a consistency index of 100%, indicating that the soil is relatively firm.
The principle involved in the relation
γsub. = γsat - γw is
When the soil exists below Water, it is in a submerged condition. When a volume V of soil is sub merged in water, then according to Archimede’s principle it displaces an equal volume of water. Thus the net mass of soil when submerged is reduced.
The uniformity coefficient of soil is given as
Uniformity of a soil is expressed qualitatively by uniformity coefficient. The larger the numerical value of Cu more is the ranges of particles.
Given for a soil sample:
Degree of saturation = 90%
Specific gravity of soil grains = 2.70
Void ratio = 0.30
The water content of the sample is
For distinguishing clays from silts in the field, a moist soil is rolled into a thread of 3 mm diameter. This test will indicate the
The test described is called 'rolling test' or ‘toughness test’ and indicates the toughness.
Which one of the following is the water content of the mixed soil made from 1 kg of soil (say A) with water content of 100% and 1 kg of soil (say B) with water content of 50%?
Weight of solids in soil A,
Weight of solids in soil B
In mixed soil,
Ww = 500 + 333.3 = 833.3 gm
Ws = 500 + 666.7 = 1166.7 gm
Which one of the following gives the correct decreasing order of the densities of a soil sample?
We know that
For dry soil, w = 0;
For saturated soil, w = ws
and for Wet soil 0 < w < ws
Thus, dry density < wet density < saturated density.
Thus submerged density < dry density
Match List-I (Property of soil) with List-ll (Laboratory equipment) and select the correct answer using the codes given below
A. Grain size
B. Specific gravity
C. Coefficient of permeability
3. Vane shear apparatus
For a given soil sample,
If Cc = 1.0 and Cu = 4.0, then the value of D30/D10 would be
⇒ D30/D10 = 2
At liquid limit, all soils possess
Which of the following methods is most accurate for the determination of the water content of soil?
A pycnometer is used to determine
In hydrometer analysis for a soil mass
R = Rh' + cm ± Ct - Cd
Rh' = Observed hydrometer reading
Cm = Meniscus correction
Ct - Temperature correction
Cd = Dispersive agent correction
Valid range for S, the degree of saturation of soil in percentage is
Degree of saturation represents the portion of volume of voids which is filled with water i.e.